We can thank the ICO boom of 2017 for that. It paved the way for scammers to earn a "quick buck" without having to deal with the regulators. Back then, crypto was in a regulatory grey area so it was pretty much the "wild west". Altcoins proved to be a wonderful tool for scammers to "hunt" down their victims for money. It's this reason why investors are so skeptical about them. Not like Bitcoin which is used more seriously in the mainstream world (although we can't say there are zero scams linked to BTC).
If you know how to play your cards right, altcoins can make you some decent profit in the short term. Otherwise, I'd suggest you stick around with Bitcoin for a while. Who knows what the fate of altcoins will be? Just my opinion